Another thing that stuck out at me in your post: being able to "confuse" experienced devs with things is not usually a good thing. As a senior, you need to be able to communicate and explain concepts clearly in a way that is _not_ confusing to people.
Finally, a question: since you are applying for a senior position, I am guessing you already have a few years of junior and mid-level jobs under your belt. Is that a correct assumption?
A great way to do this, as a senior technical person, is code review. Every note you leave has the potential to make someone a little better at their job. That means, over the course of the year, you can make 10-20 people 10-20% better - however, doing so, without pissing everyone off, is an art and takes practice.
Another place you can help is systems level thinking. Not necessarily telling people how to build something, more so about helping people understand the tradeoffs and making an informed decision.
Yet another way is to use your gift to make hard things easy, so others can learn too. Every company / team has a regression towards the mean effect. But, if you can make complex things digestible to everyone, that adds real value.
New engineers have to figure out how to write code and be productive. Mid-career engineers can make smart decisions, do things faster / more efficiently and every once and a while, pull a rabbit out of a hat. Great technical leaders turn more of the aforementioned into great technical leaders.
Books and online courses.
You already have great hands on skills. If you have the attention span for it you can improve your overall model of the system by reading books like Designing Data Intensive Applications. A good place to start for a reading list would be https://teachyourselfcs.com/.
When you have an aptitude for something there are sort of two natural directions you can go. It's possible to settle into a sort of "expert beginner" stage where you stop at a local maximum. The other option is to take the leverage that you already have and lever up again, hard. Those obscure and really useful programming tricks that you like, read some books on those too. See if you can find a conference talk where someone describes one. You probably know everything they're going to say anyway...except maybe one more trick that you can glean from that talk.
This is the path to Mastery.
You can also dig into some of the more academic content on youtube like MIT's algorithm courses stuff like that. But really I'd recommend just scratching your own itch.
In a lot of cases the answer to imposter's syndrome is "hey yeah, we all get it. Perfectly normal." In this instance though I suspect doing some reading will go a long way towards making you more comfortable.